[New discoveries in the mechanisms of apoptosis and cell survival and novel potential therapeutic strategies]. / Hücrede apoptoz ve sagkalim mekanizmalarinin kesfedilmesi ve yeni potansiyel tedavi stratejileri.

New discoveries in the mechanisms of apoptosis and cell survival have been a major breakthrough in biological sciences in recent years of the new millennium. Apoptosis is genetically programmed cell death in any nucleated cells of the organism. This type of cell death occurs through different mechanisms from those seen in necrosis and complement lysis of any cell, without affecting the neighboring cells. In the nature, apoptosis and cell survival are very important not only for the elimination of cells that acquire unstable features, become useless and detrimental to the organism, but also for the mechanisms of numerous biological events and disorders seen during the lifespan of many organisms--from the embryological period to death. The discovery of mechanisms of apoptosis and cell survival has enabled the development of new therapeutic strategies in heart diseases, cancers, neurodegenerative diseases, AIDS, and many disorders. Combination of opportunities afforded by degenerative medicine with those of new therapeutic approaches of regenerative medicine such as stem-cell therapy and somatic cell nuclear transfer will possibly introduce new horizons and rational therapeutic approaches in the foreseeable future.

Effects of protective and conventional mechanical ventilation on pulmonary function and systemic cytokine release after cardiopulmonary bypass.

OBJECTIVE: To evaluate the effects of protective and conventional ventilation with or without positive end-expiratory pressure (PEEP), on systemic tumor necrosis factor-alpha, interleukin-6 levels and pulmonary function during open heart surgery. DESIGN: Prospective, randomized clinical study. SETTING: Single university hospital. PATIENTS AND PARTICIPANTS: Forty-four patients undergoing elective coronary artery bypass grafting surgery with cardiopulmonary bypass. INTERVENTIONS: Patients ventilated with (1) protective tidal volumes (6 ml/kg, respiratory rate: 15 breaths/min, PEEP 5 cmH(2)O, n=15) group PV; (2) conventional tidal volumes (10 ml/kg, respiratory rate: 9 breaths/min, PEEP 5 cmH(2)O, n=14) group CV+PEEP and (3) conventional tidal volumes (10 ml/kg, respiratory rate: 9 breaths/min, n=15) without PEEP, group CV+ZEEP. Various pulmonary parameters, systemic TNF-alpha and IL-6 levels were determined throughout the study. MEASUREMENTS AND RESULTS: There were no differences among the groups regarding the systemic TNF- alpha and IL-6 levels. The plateau airway pressures of group PV were lower than those of groups CV+PEEP ( p=0.02) and CV+ZEEP ( p=0.001) after cardiopulmonary bypass. The shunt fraction of group PV was significantly lower than that of group CV+ZEEP 24 h after surgery ( p<0.05). Oxygenation and the alveolar-arterial oxygen difference were better in both PEEP groups than in group CV+ZEEP 24 h after the operation. CONCLUSIONS: We could not find any evidence that protective mechanical ventilation prevents some of the adverse effects of cardiopulmonary bypass on the lung, nor systemic cytokine levels, postoperative pulmonary function or length of hospitalization.